Interesting, and thanks much for the explanation. I intuitively presumed that competing spoke groups on the same side would oppose each other into symmetry. The wheel I'm looking at now doesn't appear to show alternating points --BUT it is the 1X front wheel with very small hub flanges and probably would show very little difference. I think I'll take a spare 24 paired rim and try to build on a high flange "even" hub to prove the difference to myself. I'm not sure how to approach the paper & compass proof but I'll accept it as a puzzle to work on.

Sorry for the diversion.

(what a great forum group this is)